AudioCircle

Audio/Video Gear and Systems => Cheap and Cheerful HiFi => Topic started by: Studio19atx on 7 Jun 2018, 02:51 pm

Title: Motorized Alps Pot as passive preamp
Post by: Studio19atx on 7 Jun 2018, 02:51 pm

I have seen some really nice implementation of remote controlled motorized Alps potentiometers (balanced stereo) on eBay and other market places. Can they be used effectively as a passive preamp between a DAC (without volume control) and amplifiers? Or the buffers mandatory for impedance matching? What would be possible pit falls of using the pots as passive preamp?

An example of such pot is in the link below

https://www.ebay.com/itm/Assembeld-Motor-Audio-Preamp-HW028D-Remote-Volume-Control-Board-With-ALPS-Pot/311910240726?hash=item489f4c91d6:g:KMoAAOSw8b1aABC~

Title: Re: Motorized Alps Pot as passive preamp
Post by: OSIB16 on 7 Jun 2018, 07:06 pm

That’s my current project, utilising an award winning DAC like the Metrum Octave Mk2...
(https://www.audiocircle.com/image.php?id=180989)

(https://www.audiocircle.com/image.php?id=180990)

Title: Re: Motorized Alps Pot as passive preamp
Post by: OSIB16 on 7 Jun 2018, 07:13 pm

(https://www.audiocircle.com/image.php?id=180991)

(https://www.audiocircle.com/image.php?id=180992)

Title: Re: Motorized Alps Pot as passive preamp
Post by: OSIB16 on 7 Jun 2018, 07:34 pm

(https://www.audiocircle.com/image.php?id=180994)

Title: Re: Motorized Alps Pot as passive preamp
Post by: FullRangeMan on 7 Jun 2018, 08:54 pm

You can use pots as passive preamp, just avoid use connectors instead use the direct approach:
(http://lampizator.eu/AMPLIFIERS/GM-70/april19_2009%20002.jpg)

Title: Re: Motorized Alps Pot as passive preamp
Post by: OSIB16 on 7 Jun 2018, 09:16 pm

Fullrangeman, could you explain how you have wired/connected that up. Its hard to comprehend from the photo.

Title: Re: Motorized Alps Pot as passive preamp
Post by: FullRangeMan on 7 Jun 2018, 09:36 pm

That vol pot on the table is solded direct in the middle of an interconect, none is need, no fancy box, no connectors, no knob.

Title: Re: Motorized Alps Pot as passive preamp
Post by: OSIB16 on 7 Jun 2018, 10:38 pm

Interesting idea, but I think that Studio19AX is looking for the ability to control the volume from a distance with a handheld remote.

Title: Re: Motorized Alps Pot as passive preamp
Post by: wushuliu on 7 Jun 2018, 10:49 pm

https://www.ebay.com/itm/hifi-PGA2311-Stero-Remote-Volume-Controller-audio-Preamp-pre-amplifier-with-MUTE/142620463324?hash=item2134d790dc:g:EpIAAOxy~iJQ~oa9 (https://www.ebay.com/itm/hifi-PGA2311-Stero-Remote-Volume-Controller-audio-Preamp-pre-amplifier-with-MUTE/142620463324?hash=item2134d790dc:g:EpIAAOxy~iJQ~oa9)

Title: Re: Motorized Alps Pot as passive preamp
Post by: FullRangeMan on 7 Jun 2018, 11:14 pm

Quote from: OSIB16 on  7 Jun 2018, 10:38 pm

Interesting idea, but I think that Studio19AX is looking for the ability to control the volume from a distance with a handheld remote.

This is a prob, a remote implies in a chassis and a power supply;

Title: Re: Motorized Alps Pot as passive preamp
Post by: Studio19atx on 8 Jun 2018, 01:25 pm

Quote from: OSIB16 on  7 Jun 2018, 10:38 pm

Interesting idea, but I think that Studio19AX is looking for the ability to control the volume from a distance with a handheld remote.

That’s true. I see these online and I can probably build one easily and will be relatively inexpensive.

Title: Re: Motorized Alps Pot as passive preamp
Post by: Studio19atx on 8 Jun 2018, 01:26 pm

Quote from: FullRangeMan on  7 Jun 2018, 11:14 pm

This is a prob, a remote implies in a chassis and a power supply;

I was thinking of chassis and an outward power supply (9v brick). The power is needed to rotate the motor.

Title: Re: Motorized Alps Pot as passive preamp
Post by: Studio19atx on 8 Jun 2018, 01:26 pm

Quote from: FullRangeMan on  7 Jun 2018, 08:54 pm

You can use pots as passive preamp, just avoid use connectors instead use the direct approach:
(http://lampizator.eu/AMPLIFIERS/GM-70/april19_2009%20002.jpg)

What resistor ladder are those?

Title: Re: Motorized Alps Pot as passive preamp
Post by: FullRangeMan on 8 Jun 2018, 01:58 pm

Quote from: Studio19atx on  8 Jun 2018, 01:26 pm

What resistor ladder are those?

I dont know what brand Lampizator used here, there are various options available in Poland, I use an Poland brand too>
https://www.audiocircle.com/index.php?topic=129713.180